Tennis training device using virtual targets

ABSTRACT

A virtual target system, for training multiple sports, and in an example, tennis, can include a projector system that can display a virtual target on a surface, like a tennis court. A sensor system can detect activity near the virtual target, for example, the movement or impact of a tennis ball. A processor can be linked to the projector system and the sensor system to collect activity data based on the virtual target and the activity. In one example, the display of the virtual target may or may not change in reaction to the collected activity data.

CROSS REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. application Ser. No.14/569,111, filed on Dec. 12, 2014. The entire contents of which areincorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates to a training device. Specifically, theinvention is a system and method to project virtual targets to traintennis players.

BACKGROUND

The training methods for every level of player in a sport like tenniscan be difficult to balance by level of player and the availability oftrainers or suitable partners. For very young players, it is difficultto keep their attention when the drills can consist of repetitiveswinging exercises and attempting to hit stationary targets like conesor training spots. For more advanced players, just the use of reboundnet or ball launcher may not be enough to truly test their skill as cana real opponent.

Thus, there is a need for a training device to both engage youngerplayers and provide appropriate challenges for more advanced players.

SUMMARY

A virtual target system, for training multiple sports, and in anexample, tennis, can include a projector system that can display avirtual target on a surface, like a tennis court. A sensor system candetect activity near the virtual target, for example, the movement orimpact of a tennis ball. A processor can be linked to the projectorsystem and the sensor system to collect activity data based on thevirtual target and the activity. In one example, the display of thevirtual target is not changed in reaction to the collected activitydata.

The virtual target system can also include a physical interaction devicelinked to the processor (e.g. a tennis ball launching machine) which canchange a physical condition near the virtual target (e.g. launch atennis ball at the player). The physical interaction device can changethe condition in response to the collected activity data.

In another example, the system or processor can also have a remotedevice linked to the processor and controlling at least one of theprojector system, the sensor system, the physical interaction device,and displaying the collected activity data. The remote device can be atleast one of a Smartphone, a tablet, or a laptop.

Another example of a training system to train a tennis player on atennis court uses the projector system, the sensor system, and theprocessor above but the display of the virtual target is changed inresponse to the activity data. As above, the tennis ball launchingmachine can be linked to the processor and activated in response to thecollected activity data as well as the remote device. Here, the remotedevice can provide feedback to the tennis player based on the collectedactivity data, which includes any one of information regarding the ballproximity to the virtual target, the ball impact, the trajectory of thetennis ball, or the velocity of the tennis ball.

In a further example, the changed display of the virtual target caninclude at least one of moving the virtual target, displaying a newvirtual target, changing a color of the virtual target, changing a sizeof the virtual target, displaying a virtual trajectory of the tennisball on the court as it moved toward the virtual target, or displayingthe velocity of the tennis ball as it moved toward the virtual target.

The invention can also include a method of training a tennis player on atennis court by projecting a virtual target on the court using theprojector system, sensing activity near the virtual target using thesensor system, collecting, using the processor, activity data based onthe virtual target and the activity, and changing the virtual targetbased on the activity data. The activity data collected can be similarto that described above.

In an example, the changing step can include moving the virtual target,displaying a new virtual target, changing a color of the virtual target,changing a size of the virtual target, displaying a virtual trajectoryof the tennis ball on the court as it moved toward the virtual target,or displaying the velocity of the tennis ball as it moved toward thevirtual target. The method can also include the tennis ball launchingmachine.

BRIEF DESCRIPTION OF THE DRAWINGS

This invention is described with particularity in the appended claims.The above and further aspects of this invention may be better understoodby referring to the following description in conjunction with theaccompanying drawings, in which like numerals indicate like structuralelements and features in various figures. The drawings are notnecessarily to scale, emphasis instead being placed upon illustratingthe principles of the invention.

The drawing figures depict one or more implementations in accord withthe present teachings, by way of example only, not by way of limitation.In the figures, like reference numerals refer to the same or similarelements.

FIG. 1 is a side view of the invention indoors;

FIG. 2 is a top view of a court with virtual targets projected thereon;

FIGS. 3A-3C illustrate different examples of configurations of thesystem;

FIGS. 4A and 4B illustrate an example of the system of the invention;

FIG. 5 is a diagram of the system, including the processor;

FIG. 6 illustrates another example of the system;

FIG. 7 is a flow chart of an example of a method of the invention; and

FIG. 8 illustrates a further example of the present invention.

DETAILED DESCRIPTION

In the following detailed description, numerous specific details are setforth by way of examples in order to provide a thorough understanding ofthe relevant teachings. However, it should be apparent to those skilledin the art that the present teachings may be practiced without suchdetails. In other instances, well known methods, procedures, components,and/or circuitry have been described at a relatively high-level, withoutdetail, in order to avoid unnecessarily obscuring aspects of the presentteachings.

FIGS. 1 and 2 illustrate an example of present invention. In thisexample, a tennis court is illustrated, but the invention can be used insimilar situations. A tennis court 10 has a net 12 typically dividingthe court 10 in half. A standard tennis court is 36 feet wide to theoutside lines and 78 feet long, making the distance for half the court39 feet. The net 12 is at half court and typically 3 feet high in thecenter.

FIG. 1 illustrates an example where the court 10 is indoors. A virtualtarget training system 100 can be mounted on a ceiling 16 of the indoorcourt 10. The system 100 can include a projector 102, a sensor 104, anda processing unit 106. The projector 102 and sensor 104 are coupled tothe processor 106. The processor 106 can coordinate the projector 102and sensor 104 as follows.

The processor 106 can be, in one example, a desktop, laptop, or portablecomputer programmed to project images to the projector 102 and receiveinput from the sensor 104. The projector 102 can be any projector 102configured to project images from the processing unit 106. The projector102 can be mounted above the court 10, or, using a short or ultra shortthrow projector, the projector 102 can be mounted closer to a surface 14of the court 10. For example, a regular projector with a 1.5:1 throwratio has to be approximately 7.5 feet away from the surface to projecta 60-inch wide image. A short throw projector with a throw ratio of0.6:1 can project the same image when placed less than three feet away,while an ultra short throw projector with a 0.37:1 throw ratio canproject the same image from just 1.85 feet away. One or more projectors102 can be modified to have a projection area 108 that covers portions,half, or the entire court 10. Further, the system 100 can be fixedlymounted or portable, depending on the configurations below and thelocation.

The sensor 104 has a sensor area 110 approximately coincident with theprojection area 108. The sensor 104 can be a camera, or any other motionsensing device. In one example the camera 104 can detect objects ormotion in the sensor area 110 and relay that information back to theprocessor 106. The sensor 104 can be a camera, including a basic“webcam,” as long as it can transmit information back to the processor106.

FIGS. 3A-3C illustrate examples of different combinations of projector102 and sensor 104 placement to project areas 108, 110 on to the court10. FIG. 3A illustrates an example where the projector 102 and sensor104 are mounted to the ceiling 16 over the court 10. This is mostadvantageous for indoor courts 10. FIG. 3B illustrates a short or ultrashort throw projector 102 near the surface 14. The sensor 104 can beagain close to the projector 102, keeping its sensor area 110 close tothe court surface 14. In this way, the system 100 can minimize thesensing of movements above a certain height above the court 10. FIG. 3Cseparates the projector 102 and sensor 104, allowing one to be at aheight above the other. In the illustration, the projector 102 is closerto the court surface 14 while the sensor 104 is higher up. The examplesin FIGS. 3B and 3C can be used for both indoor and outdoor courts. Notethat bright lighting can affect the visibility of the images from theprojector 102.

The system 100 can be programmed to display a virtual target 200 on thecourt surface 14. The virtual targets 200 can be any geometric shape orimage, from bullseyes to images of professional tennis players. Further,moving virtual targets 202 can be displayed, moving across the court 10in any direction or pattern. The processor 106 can coordinate theprojected images 200, 202 with the feedback received from the sensor 104and can change the images 200, 202 accordingly. For example, a virtualbullseye 200 is projected on the surface of the court 14. A player 18hits a ball 20 in an attempt to strike the bullseye 200. The sensor 104senses the motion of the ball 20 and the processor 106 can determine theposition at which the ball 20 impacts the surface of the court 14.Whether the ball 20 “hits” or “misses” the target 200, 202 can determinea change in the projected targets 200, 202 or acknowledge a tally.

To be explicit, one example of the system 100 does not have any physicaltargets to be hit. All of the targets 200, 202 presented to the user arevirtual by the fact that they are images projected by the projector 102.Impacts to the target 200, 202 are not registered by any physical means(e.g., pressure transducer, electrical or magnetic detection). Theimpacts are detected solely by the position of the ball 20 detected bythe sensor 104 and relating that to the position of the virtual targets200, 202. Thus, the surface 14 of the court 10 does not needmodification to accommodate physical sensors, and the targets 200, 202can be “moved” by virtue of the change in the projected image, nophysical movements of the targets are required.

In different examples for hit/miss options, the target 200, 202 canincrease or decrease in size, change shape or color, stop or startmoving, change movement speed or pattern, or exhibit some graphicalchanges. Further examples, can include sound effects to match thehit/miss options. In an example, the targets 200, 202 can “break” whenhit, which would include corresponding graphics and matching soundeffects, like breaking glass, or the like. In examples, the system 100can accommodate audio outputs to an existing audio system or can beequipped with its own amplifiers and speakers, etc.

Additionally, as illustrated in FIGS. 4A and 4B the sensor 104 can trackactual movement in addition to just the point of impact of the ball 20.This can allow the system 100 to compute trajectories and velocities ofthe ball 20 and use them accordingly. The system 100 can be adapted touse multiple types of sensors 104 or specifically calibrate the sensorsfor this task. In an example, two sensors can be used, a camera 104A anda radar gun 104B (and its accompanying sensor area 112), to provide allof the data to the processor 106 necessary to make thetrajectory/velocity determinations. Thus, for training, the system candetermine if the ball 20 passed a certain point at a certain height,thus compensating to act as if an opponent was standing at the target200 and not just aiming at the surface 14. The system can project thetrajectories 204 on the surface 14 and provide some other indication ofspeed (e.g. color changes).

Further, the system 100 can include one or more tennis ball launchers114 linked to the processor 106. The launchers 114 can be controlled to“return” a ball to the player 18, as if an opponent hit the ball asdelivered by the player 18. This can more accurately simulate gameconditions since the return ball 22 can be launched to the player 18based on the trajectory/velocity of the player's ball 20. FIGS. 4A and4B illustrate that the ball 20 delivered by the player has a certainposition in space. Instead of waiting for the ball 20 to impact thesurface 14, the processor 106 can instruct launcher 114B to launch areturn ball 22 since it is the closest to where the player ball 20 wouldhave been returned from if a real opponent hit it. If thetrajectory/velocity differed, other launchers 114A, 114C can beinstructed to launch the return ball 22. Alternately, a single launcher114 can have an oscillator to nearly mimic the return ball position.

The system 100 can thus more accurately mimic a match against a realopponent. The projector 102 can place and move the target 200, 202 tosimulate the position of the opponent. The sensor(s) 104 can track themovement of the player's ball 20 over the court. The processor 106 canthen have the launcher(s) 114 fire a return ball 22 from a position thatwould approximate where the player's ball 20 would have been returnedfrom. The processor 106 can also attribute a “speed” to the “opponent”to determine where to next place the target 200, 202 and if the“opponent” would be able to return the player's volley.

In another example, as illustrated in FIG. 5, the system 100 can becontrolled remotely through any portable device 116. This can includethe use of an application on a Smartphone, tablet, laptop, or any otherdevice remotely communicating with the processor 106. In one example,the typical projector 102 and sensor 104 can be physically connected tothe processor 106. The processor 106 can be in a laptop or desktopcomputer 300 with the appropriate ports 302 (VGA, USB, etc.), and thecomputer 300 can have a display 304 and one or more input devices 306(e.g., keyboard, mouse, pointing device, touch screen, etc.). Thecomputer 300 can further have a memory 308 to store the software neededto operate the system 100, including the drivers for the projector 102and sensors 104, and a CPU 310 to run the software. The launcher 114 canbe linked to the computer 300 either by wire, or wirelessly, e.g.through wireless antenna 312. The launcher 114 and computer 300 cancommunicate via networking protocols, Bluetooth, etc.

Further, the portable device 116 can also be remotely or wirelesslylinked to the computer 300. As above, the portable device can be assimple as a multi-button remote to a tablet running an application. Aspeaker 314 can also be included to provide audio commentary, tips,music, or sound effects appropriate to the training regime or targets200, 202 being projected. Network connectivity can also be used. In thisexample, the trainer need not be physically present with the player 18.The trainer can be in a different area of the court, or even the world,but can control the training from the networked portable device 116.

Using the system 100 with a speaker 314, a trainer can provide commentsand guidance to the player 18, in real time as the player 18 engages thetargets 200, 202. Alternately, the system 100 can havepreprogrammed/pre-recorded comments so the player 18 can practicewithout the need for a human trainer. Alternately, using the portabledevice 116, a single trainer can engage multiple players of variousskill levels by changing the difficulty as that player enters the court10. Thus, novice and experienced players can be trained during the sametraining session, on the same court, to maximum advantage. Alternately,the portable device 116 can be controlling multiple systems 100 overmultiple courts at the same time, each court accommodating a differentskill level of player or just multiple groups of players. The system 100can also, in another example, recognize the individual players orcertain marking indicia, to automatically change the skill level to theappropriate skill level for that player by using the sensor 104 todetect the player or indicia (e.g. face recognition, colored shirts,etc.).

FIG. 6 illustrates another example, this time where the player 18 is onthe same side as the system 100. The player 18 can be placed within theprojection and sensor areas 108, 110. The projector 102 can project avirtual tennis ball 204 and the player 18 can be instructed to hit the“ball” 204 with the appropriate forehand or backhand swing. The sensors104 can detect the player's movement and determine if the swing was inproper form or if the ball 204 was correctly hit. In addition, since thesensor 104 can be a camera, in one example, the system 100 can play backan image of the player's swing for analysis. The image can be playedback in real time to the portable device 116 for a trainer supervisingthe player, or stored in memory 308 and played back at a later time forthe trainer, the player, or both. Further, a real ball 20 can also beused with the system to determine swing proficiency. The trainer or thelauncher 114 can direct a ball for the player 18 within the areas 108,110 as well.

FIG. 7 illustrates a method of training the tennis player 18 on thetennis court 10 using at least the tennis ball 20. The method caninclude the steps of projecting a virtual target 200 on the court 10using a projector system 102 (step 300), sensing activity near thevirtual target 200 using a sensor system 104 (step 302), collectingactivity data based on the virtual target and the activity (step 304),using the processor 106, and changing the virtual target 200 based onthe activity data (step 306). The activity data can be at least one ofinformation regarding a proximity of the ball to the virtual target, animpact of the ball over the virtual target, a trajectory of the tennisball, or a velocity of the tennis ball.

Further, the changing step can have at least one of the steps of movingthe virtual target 200 (step 308), displaying a new virtual target 202(step 310), changing a color of the virtual target 200 (step 312),changing a size of the virtual target 200 (step 314), displaying avirtual trajectory 204 of the tennis ball 20 on the court 10 (step 316),and displaying the velocity of the tennis ball 20 (step 318). Anadditional step of activating a tennis ball launching machine 114 inresponse to the collected activity data (step 320) can also be included.

Turning now to other sports, this present invention can be easilyadapted for ping pong. Many, if not all, of the same elements can apply,albeit on a smaller scale. Further, examples of the present inventioncan be used, as illustrated in FIG. 8, for golf. Here, two projectors102A, 102B (projection projector areas 108 and 118) and two sensors104A, 104B (having sensor areas 110 and 112) can be used to providevirtual targets and training images to a golfer 30. One pair ofprojectors/sensors 102A, 104A can project the ball 32 location ormonitor the golfer 30 and her swing. Alternately, the system cangenerate a virtual ball. A second projector/sensor 102B, 104B pair canproject the fairway on a wall or screen 34 and determine the ball flightpath.

Additionally, using a similar configuration, an example of the inventioncan be used for baseball batting practice. The launcher 114 can now be abaseball pitching machine that projects the balls through thescreen/wall 34. It can also be used for pitching practice, or forfootball quarterback practice by projecting batters, strike zones, orreceivers on the wall/screen 34.

This system can be used for numerous other sports, namely any otherracket, bat or club sport (e.g. squash, badminton, racket ball, handball, cricket, croquet, etc.) or ball sports like soccer and volleyballin accordance with the above examples.

While the foregoing has described what are considered to be the bestmode and/or other examples, it is understood that various modificationsmay be made therein and that the subject matter disclosed herein may beimplemented in various forms and examples, and that the teachings may beapplied in numerous applications, only some of which have been describedherein. It is intended by the following claims to claim any and allapplications, modifications and variations that fall within the truescope of the present teachings.

What is claimed is:
 1. A virtual target system, comprising: a projectorsystem displaying a virtual target on a surface; a sensor systemdetecting activity near the virtual target; a processor linked to theprojector system and the sensor system to collect activity data based onthe virtual target and the activity; wherein the displaying of thevirtual target is not changed in reaction to the collected activitydata.
 2. The virtual target system of claim 1, further comprising: aphysical interaction device linked to the processor and changing aphysical condition near the virtual target; wherein the physicalinteraction device changes the condition in response to the collectedactivity data.
 3. The virtual target system of claim 2, wherein theprocessor further comprises: a remote device linked to the processor andcontrolling at least one of the projector system, the sensor system, thephysical interaction device, and displaying the collected activity data.4. The virtual target system of claim 3, wherein: the surface is atennis court; the activity is a movement of a tennis ball; the physicalinteraction device is a tennis ball launching machine; and the remotedevice is at least one of a Smartphone, a tablet, or a laptop.
 5. Atraining system to train a tennis player on a tennis court using atleast a tennis ball, comprising: a projector system displaying at leastone virtual target on the court; a sensor system detecting activity nearthe virtual target; and a processor linked to the projector system andthe sensor system to collect activity data based on the virtual targetand the activity; wherein the activity data is at least one of motion ofthe tennis ball in proximity to the virtual target, an impact of thetennis ball on the tennis court over the virtual target, a trajectory ofthe tennis ball, or a velocity of the tennis ball; and wherein thedisplaying of the virtual target is changed in response to the activitydata.
 6. The training system of claim 5, further comprising: a tennisball launching machine linked to the processor and activated in responseto the collected activity data.
 7. The training system of claim 6,wherein the processor further comprises: a remote device linked to theprocessor and controlling at least one of the projector system, thesensor system, the tennis ball launching machine, and displaying thecollected activity data.
 8. The training system of claim 7, wherein theremote device provides feedback to the tennis player based on thecollected activity data, wherein the feedback includes at least one ofinformation regarding the ball proximity to the virtual target, the ballimpact, the trajectory of the tennis ball, or the velocity of the tennisball.
 9. The training system of claim 7, wherein the changed display ofthe virtual target comprises at least one of moving the virtual target,displaying a new virtual target, changing a color of the virtual target,changing a size of the virtual target, displaying a virtual trajectoryof the tennis ball on the court as it moved toward the virtual target,or displaying the velocity of the tennis ball as it moved toward thevirtual target.
 10. A method of training a tennis player on a tenniscourt using at least a tennis ball, comprising the steps of: projectinga virtual target on the court using a projector system; sensing activitynear the virtual target using a sensor system; collecting, using aprocessor, activity data based on the virtual target and the activity,and further comprises the step of collecting at least one of informationregarding a proximity of the ball to the virtual target, an impact ofthe ball over the virtual target, a trajectory of the tennis ball, or avelocity of the tennis ball; and changing the virtual target based onthe activity data.
 11. The method of claim 10, wherein the changing stepcomprises at least one of the steps of: moving the virtual target;displaying a new virtual target; changing a color of the virtual target;changing a size of the virtual target; displaying a virtual trajectoryof the tennis ball on the court as it moved toward the virtual target;or displaying the velocity of the tennis ball as it moved toward thevirtual target.
 12. The method of claim 10, further comprising the stepof activating a tennis ball launching machine in response to thecollected activity data.